Nexus 6, Bricked after trying to root Marshmallow

Unlocked/rooted nexus 6 stock no roms/kernals. Earlier today I went to flash the security update so I used nexus toolkit, and I noticed they had the preview for M so I just updated to that. It updated fine and I went to root the phone, only I guess you cant just use the toolkit to root any more because it wouldn't load, it said it was corrupted, so I just re-flashed back to the original update I was on 5.1.1 LMY48l. It installed but and ran through the optimizing apps, once it finished it rebooted and did it again. It kept rebooting and optimizing for a few hours. I read it could be a problem with the cache so I wiped it in recovery mode. Everywhere I read said to factory reset, the only problem is I forgot to backup and now I cant access the files through usb. Is there any was I can recover the files before I factory reset or am I just SOL? Thanks in advanced